dc conduction of stable ultrathin Pt films below the percolation threshold

Samples of highly stable platinum films with mass thickness from 0.12 to 0.3 nm have been deposited on amorphous alumina surfaces in vacuum under carefully controlled conditions. An alumina cover layer was deposited in order to seal the ultrathin metal structures and provide long-time stability of samples. The thickness dependence of the dc conductance of the highly stable films was measured both at room and liquid nitrogen temperatures and is reported. The temperature dependence of the conductance was measured in the temperature range from 100 to 350 K and thermally activated conductance in the films was observed as the dominant process below the onset of charge transport in the metal network within the sample.